Traditional methods for the analysis of hydrocarbon samples require lengthy, complicated techniques that often do not provide sufficient information about the samples. Some involve a series of traps and multiple valves or columns (Paraffins, Iso-paraffins, Olefins, Naphthenes and Aromatics or PIONA), lengthy chromatographic programs (Detailed Hydrocarbon Analysis or DHA), and some only give boiling range information (Simulated Distillation or SIMDIST). The PIONA analysis does not accurately speciate some of the heavier components in gasolines (especially in the C9–C12 range), due to chromatographic overlapping of compounds and the lack of absolute standards for these species. Detailed Hydrocarbon Analysis (DHA) suffers from some of the same lack of specificity problems, and involves relatively lengthy analyses (up to 2 hours each). While SIMDIST provides accurate information on quantities of hydrocarbons within specific boiling ranges, it does not provide any speciation information on these hydrocarbons. A method is needed to provide quantitative information about complex hydrocarbon mixtures that includes speciation within various boiling point ranges. Such information would be particularly useful in the gasoline range.
Additionally, when using the available analytical techniques as described above, the hydrocarbon sample must first be distilled into a number of cuts. The cuts are then analyzed. This procedure requires:                1) A large quantity of the sample for distillation, that may not be available.        2) Distillation of the sample into multiple cuts        3) Determination of the composition of each cut.None of the typical compositional methods can provide accurate quantification for the high boiling range cuts (e.g., 204° C.+). It would be useful to provide a method that does not require separate cuts of the sample and one that can provide data for high boiling ranges.        
The Townsend Discharge Nitric Oxide Chemical Ionization (TDNOCI) method has been developed and applied to kerosene and diesel range hydrocarbon samples as discussed in “Townsend Discharge Nitric Oxide Chemical Ionization Gas Chromatography/Mass Spectrometry for Hydrocarbon Analysis of the Middle Distillates”, I. Dzidic, H. A. Petersen, P. A. Wadsworth, and H. V. Hart, Analytical Chemistry, 1992, 64, pp. 2227–2232, which is hereby incorporated by reference.
Previously, this method was not applicable to gasoline range samples, as it did not provide for quantification or identification of olefinic hydrocarbons, which are commonly present (5–45 wt %) in catalytically or thermally cracked gasoline samples. Additionally, as mentioned above, PIONA and DHA analyses are not as specific as is desired for accurate quantification of heavier components in the gasoline samples. SMIDIST analysis alone does not provide specific hydrocarbon type data.
It would be advantageous to adopt the TDNOCI method for use with gasoline range samples including those with olefin constituents.